1. Field of Invention
This invention relates to hydraulic brake systems. In particular, this invention relates to improved one person brake bleeder screws useful for removing entrapped gases from a vehicle's hydraulic wheel brake system.
2. Prior Art
In recent years improved methods for the bleeding of automobile hydraulic brake systems have been designed in order to eliminate air or gases present in these systems. For example, U.S. Pat. No. 4,479,511 describes a one person check valve and coupler assembly which is attached to a standard brake bleeder valve on a vehicle for the bleeding of the brake system. It incorporates a coupler between a one-way check valve and a standard bleeder valve. The coupler is a threaded nut which is threaded onto the inlet end of the valve body of the one-way check valve. The outer end of this threaded nut is slotted to slip over and behind the nipple of a standard bleeder valve. This mechanism discloses one method for the bleeding of a standard hydraulic brake bleeder valve by one person.
U. S. Pat. No. 4,524,800 describes a one-way brake bleeder check valve with a sealing cap. This one-way brake bleeder check valve is comprised of a valve body with a longitudinal passageway and an adjustable valve sealing cap which is screwed over the valve body. Contained within the valve is a compression spring pressing on a ball valve which seals off the passageway to the hydraulic wheel brake cylinder prior to the brake bleeding process. When the brake pedal is pressed, the pressure within the brake system forces the ball valve open and releases any trapped gases in the system. While this device is quite useful in the bleeding of hydraulic wheel brake cylinders, it does not replace conventional brake bleeder valves. Further, it requires two elements, 22 and 34 for successful operation.
U. S. Pat. No. 4,706,705 describes a check valve comprised of a generally tubular body including a cylindrical base and a guide sleeve. This check valve also uses a ball valve as a sealing element with two compression springs pressing on various elements of the check valve. It is considerably more complicated than the instant invention and does not replace conventional brake bleeder valves.
U. S. Pat. No. 4,524,793 describes another complicated automatic valve for bleeding air from a hydraulic fluid reserve. It is comprised of several elements which are screwed into a brake valve for bleeding of the line. Its very complexity contrasts with the simplicity of the instant invention.
While some of these patents disclose efficient methods for the removal of gases from hydraulic brake lines, many are quite complex and none can rep-ace the standard brake valve while still permitting the bleeding of a brake system by one person.
Therefore, it is an object of this invention to provide an improved brake bleeder screw for use in bleeding hydraulic wheel brake systems.
It is another object of this invention to replace the standard brake bleeder valve contained on many commercial vehicles with an improved brake bleeder screw.
It is a still further object of this invention to provide an efficient, easy to use, inexpensive, one person brake bleeder screw for use in the bleeding of hydraulic wheel brake systems.
These and other objects and features of the present invention will become apparent to those skilled in the art from a consideration of the following detailed description, drawings and claims. The description along with the accompanying drawings provide a selected example of construction of the device to illustrate the invention.